Notice: Undefined index error messages

I’m running an emonBase and keep it updated, but still seem to have a huge number of notices on the setup “My Account” page, which relate to line 36, e.g.

Notice: Undefined index: ko.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
but each line has a different index:
Notice: Undefined index: se.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: de-at.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: ar-dz.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: invalid.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: calendar.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: ordinal.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36
Notice: Undefined index: locale.js in /var/www/emoncms/Modules/user/profile/profile.php on line 36

It looks like a lot of them relate to language packs (using default English pack - but lots of “nulls” in the dropdown menu).
The system is working and logging data, but something is clearly amiss.
Can anyone suggest a cause/fix?